Question

我正在尝试对字母频率程序进行编码，该程序对.txt文件中的字母字符进行计数，并将频率数据显示在3列表格中（字母，频率，*条形图）。我目前除了条形图之外还有正确打印所有内容的代码。我不知道如何打印出星号条形图。任何指导将不胜感激。感谢。

Letter Count Bar
------ ----- ---
A      4     ****
B      8     ********
and so on...

这是我的代码：

final static int AlphabetSize = 26;
final static Scanner cin = new Scanner(System.in);
final static PrintStream cout = System.out;
final static int MaxBarLength = 50;

public static void main(String[] args) {
    String fileName;

    // get the file name
    cout.print("Enter the file name: ");
    fileName = cin.nextLine();

    // process the file
    try {
        processFile(fileName);
    }
    catch (IOException e) {
        e.printStackTrace();
    } // end try

} // end main

static void processFile(final String fileName) 
        throws FileNotFoundException, IOException 
{
    FileInputStream inFile = new FileInputStream(fileName);
    int inputValue;

    // declare other variables you need
    int [] counters = new int [26];
    int alpha = 0;
    int num = 0;

    // get the first character from file
    inputValue = inFile.read();
    while (inputValue != -1) {
        char ch = (char) inputValue;

        // add code to process this character
        int c = char2int(ch);
        if (c >= 0) {
            counters[c]++;
            alpha++;
        } else {
            num++;
        }

        // read next input character
        inputValue = inFile.read();
    } // end loop

    inFile.close();

    // generate appropriate output
    System.out.println("\nThe data file has " + alpha + " alphabetic, and " + num + " other characters.\n");
    display(counters);

} // end function

static void display(final int [] counters) {
    // write code for this function
    System.out.println("Letter" + " " + "Count" + " " + "Bar");
    System.out.println("------" + " " + "-----" + " " + "---");
    printChars(counters);

} // end function

// char2int is complete
static int char2int(final char arg) {
    if (!Character.isLetter(arg))
        return -1;
    else
        return (int) Character.toUpperCase(arg) - (int) 'A';
} // end function


// function printChars writes n copies of the character c to the
// standard output device
static void printChars (final int [] counters) {
    // write the code
    for (int i = 0; i < 26; i++){
        System.out.printf("%c%7d\n", i + 'A', counters[i]);
    }
} // end printChars

Answer 1

如果你想打印一个＆＃39; *＆＃39;每次出现一封信：

// function printChars writes n copies of the character c to the
// standard output device
static void printChars (final int [] counters) {
    // write the code
    for (int i = 0; i < 26; i++){
        System.out.print("%c%7d\n", i + 'A', counters[i]);
        for(int j = 0; j < counters[i]; j++) {
            System.out.print("*");
        }
        System.out.println();
    }
}

如果你只想表达一个“亲戚”。条形图，您需要将分数标准化。首先计算乘数以对分数进行标准化，然后应用：

// function printChars writes n copies of the character c to the
// standard output device
static void printChars (final int [] counters) {
    float MAX_BAR_LENGTH = 20.0;
    int maxScore = 0;
    for (int i = 0; i < 26; i++){
        if(counters[i] > maxScore) {
            maxScore = counters[i];
        }
    }
    float multiplier = maxScore > 0 ? MAX_BAR_LENGTH / maxScore : 0;

    // write the code
    for (int i = 0; i < 26; i++){
        System.out.print("%c%7d\n", i + 'A', counters[i]);
        for(int j = 0; j < (multiplier * counters[i]); j++) {
            System.out.print("*");
        }
        System.out.println();
    }
}

Answer 2

对于我正在寻找的格式，我在@Jason的代码中编辑了一些内容。

以下是修订后的工作代码：

static void printChars (final int [] counters) {
// write the code
    for (int i = 0; i < 26; i++){
        System.out.printf("%c %7d     ", i + 'A', counters[i]);
        for(int bar = 0; bar < counters[i]; bar++){
            System.out.print("*");
        }
        System.out.println();
    }
} // end printChars

使用星号的水平条形图

2 个答案: